2 * Copyright (c) 2015 Cisco Systems, Inc. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.yangtools.yang.model.api.meta;
10 import com.google.common.annotations.Beta;
11 import java.util.Collection;
12 import java.util.List;
13 import java.util.Optional;
14 import java.util.stream.Collectors;
15 import java.util.stream.Stream;
16 import org.eclipse.jdt.annotation.NonNull;
17 import org.eclipse.jdt.annotation.Nullable;
18 import org.opendaylight.yangtools.yang.common.Empty;
21 * Effective model statement which should be used to derive application behaviour.
23 * @param <A> Argument type ({@link Empty} if statement does not have argument.)
24 * @param <D> Class representing declared version of this statement.
26 public non-sealed interface EffectiveStatement<A, D extends DeclaredStatement<A>> extends ModelStatement<A> {
28 * Returns {@link StatementOrigin}, which denotes if statement was explicitly declared in original model or inferred
29 * during semantic processing of model.
32 * Implementations are required to return a {@link StatementOrigin}, consistent with {@link #getDeclared()}
33 * nullness. This is what the default implementation does and hence this method should never be explicitly
34 * implemented -- unless there is significant cost to the {@link #getDeclared()} implementation.
36 * @return statement origin.
38 default @NonNull StatementOrigin statementOrigin() {
39 return getDeclared() != null ? StatementOrigin.DECLARATION : StatementOrigin.CONTEXT;
43 * Returns statement, which was explicit declaration of this effective
46 * @return statement, which was explicit declaration of this effective
47 * statement or null if statement was inferred from context.
49 @Nullable D getDeclared();
52 * Returns a collection of all effective substatements.
54 * @return collection of all effective substatements.
56 @NonNull List<? extends @NonNull EffectiveStatement<?, ?>> effectiveSubstatements();
59 * Find the first effective substatement of specified type.
61 * @param <T> substatement type
62 * @param type substatement type
63 * @return First effective substatement, or empty if no match is found.
66 default <T> Optional<T> findFirstEffectiveSubstatement(final @NonNull Class<T> type) {
67 return effectiveSubstatements().stream().filter(type::isInstance).findFirst().map(type::cast);
71 * Find the first effective substatement of specified type and return its value.
73 * @param <T> substatement type
74 * @param <V> substatement argument type
75 * @param type substatement type
76 * @return First effective substatement's argument, or empty if no match is found.
79 default <V, T extends EffectiveStatement<V, ?>> Optional<V> findFirstEffectiveSubstatementArgument(
80 final @NonNull Class<T> type) {
81 return findFirstEffectiveSubstatement(type).map(EffectiveStatement::argument);
85 * Find all effective substatements of specified type and return them as a stream.
87 * @param <T> substatement type
88 * @param type substatement type
89 * @return A stream of all effective substatements of specified type.
92 default <T extends EffectiveStatement<?, ?>> Stream<T> streamEffectiveSubstatements(final @NonNull Class<T> type) {
93 return effectiveSubstatements().stream().filter(type::isInstance).map(type::cast);
97 default <Z extends EffectiveStatement<?, ?>> @NonNull Collection<Z> collectEffectiveSubstatements(
98 final @NonNull Class<Z> stmt) {
99 return streamEffectiveSubstatements(stmt).collect(Collectors.toUnmodifiableList());